autohelm - sailing by the wind.

[dmmbruce]

I know this is slighly off the point for the original post, but why bother? I don't mean this rudely but it should not be needed if you have a half decent boat.

Either, a.) You want to go from A to B. In which case you use a normal autopilot gps type system and go in a known straight line.

Or, b.) You want to sail from A generally in the direction of B, with no hassle and you will sort out the detail as you go, every hour or so.

With choice b.)All you have to do is set up your sails so that the boat is balanced. That means that you get the foresails and the mainsail adjusted so that there is no need to touch the tiller/wheel. This method is sea kindly (and comfortable) boat kindly (and comfortable) crew kindly (and appreciated) and it is easy.

All very simple if you have sea room and you are not afflicted with the desire to go as fast as possible all the time.

Hope this saves you £1500!

Mike

 

[ytd]

we have the ability on out ST6000 but rarely use it. It is most useful when trying to make ground to windward shorthanded but in light winds it steers the boat all over the place as it is confused by apparent wind changes. Whereas a human helmsan will let the sails luff for a bit when the boat runs out of wind the pilot is frantically trying to bear away. In 15 knots it does a good job. In 25 knots a gust will back the sails and it doesn't react fast enough meaning you have to jump up and reset onto the new tack. Off the wind, trim has less effect on boatspeed, so a compass or waypoint course is better.

 

[Bosun Higgs]

I know this is slighly off the point for the original post, but why bother? I don't mean this rudely but it should not be needed if you have a half decent boat................... All you have to do is set up your sails so that the boat is balanced.

I think your comments might be answered by the post below yours, but I reckon sail trim isnt the answer at all. When handling the boat manually, you constantly adjust the helm as the apparent wind changes. If you are on a compass course you have to sail more free of the wind so that when the apparent wind changes and the boat effectively luffs up you dont go into irons or tack. So you sail maybe 5 degrees maybe more free of the wind than you would do if you were helming manually.

I'm less sure what would happen if you tried to do the job wholly by sail trim. I cant see how the boat would alter course a bit as the wind oscillated, and I certainly can see problems if you were hard on the wind and the heel angle changed in a gust since balancing the boat as you describe means balancing it for a particular heel angle / pressure to round up.

I was hoping that wind steering by autohelm would get round this but the consensus seems to be that it wont.

 

[Oyvind]

I've sailed a fair bit on my buddy's Cyclades 43, which has a state-of-the art Raymarine autopilot setup with all the bells and whistles.

Beating up the North Sea this spring, against a force 6-7 with 4-5 meter waves, the wind steering performed absolutely flawlessly. Our experience was that the autopilot actually did a better job in keeping the boat on the optimum course than we were able to by hand, especially considering the fatigue factor as we were well into our second day of a double handed race. The wind wane would pick up any relative variations in the wind and instantly correct the course as the boat crashed and gyrated through and over the waves.

Mind you, this is not exactly a budget installation. IMHO you do need a sufficiently strong and fast drive unit for wind steering to work well when the wind picks up.

 

[Bosun Higgs]

Interesting comment. There's you saying that a Raymarine system works and others above you saying it doesnt. So unless one of you is mistaken, there must be an issue of settings.

Any chance that you can getr the spec of your pals system and let me have it. Are there response setting you can put into the Raymarine or the Navman to get the system to preform with the wind?

My rudder drive is up to the job I believe - its a Simrad HLD 350 hydraulic mounted on the rudder stock and which goes from one extreme to the other in 10 secs adjustable. I can vouch for that since at the mo its sometimes doing that when not needed!

 

[nimbusgb]

I am surprised at the preceding comments on Raymarine kit and wind relative steering.

I got my combination of e80, st60+, S1 gyro pilot computer , saildrive 1, and 6000 control head all installed and working last trip out to the boat. I found its ability to hold a wind relative course very impressive. Both off the wind and on it. In fact off the wind with the cruising chute up it was particularly good. I did take a fair amount of time actually setting up the system using the calibration and commisioning modes.

As to why I need an electronic autopilot - with a very inexperienced and wary family crew the ability to leave the wheel and go and help the youngsters on the foredeck while actually pressed under sail was invaluable. Just being able to leave the wheel and fetch a drink, sandwich or talk to SWMBO was a major drawcard.

One unexpected bonus was the auto tack feature. With the boat on one tack I'd hit the AP enable button, prepare the crew, hit the auto tack and step around to the leward winch to sheet in and grind.

Being a gadget freak I have the wireless remote control too and I had fun using the course steering remotely.

I'm sure that having Fred available to take the wheel contributed greatly to SWMBO's enjoyment of our sailing.

Now all I have to do is either sort out a remote dropping anchor winch so that I can do anchoring completely single hand.

 

[Bosun Higgs]

Interesting comment nimbus, coming as it does from someone with a tech background. Can you clarify:

1/ will it steer hard on the wind, by which I mean within a degree or two or luffing up, or do you have to sail a bit free of the wind to avoid accidental luffing as the apparent wind moves about?

2/ what parameters are involved in setting it up and what response time does the pilot ram have?

 

[nimbusgb]

I wouldn't say hard on the wind was even tried in earnest, probably we didnt bother to push beyond 45 degrees . It could certainly hold a course better than a 'trainee helm' and my son learned that pushing the button to kick in the AP was a way to get things back under control when his brain got the classic over correcting problem.

The fluxgate compass, st60 wind and the autopilot computer all needed calibration cycles. Sailing in circles at a given rate etc. I probably did those 3 or 4 times before things worked properly. ( Does the raymarine ap 'learn' or does it start from scratch every time anyone? )

My wheel only does 1.5 turns lock to lock, the ram is fitted to act about 200mm from the centre of the rudder post, response time 35 degrees to 35 degrees is about 8 seconds IIRC so it is pretty responsive around the centre of the arc.

The various settings on the st6000 do make a difference ie. response rate , boat type ( sail / power ).

 

[tcm]

imho, the facilty on raymarine kit to sail on a wind angle is a gimmick - cos if the wind shifts 15degrees it stops, and throws error "wind shift". Rubbish.

 

[lw395]

Can you get one for a musto skiff?

imho, the facilty on raymarine kit to sail on a wind angle is a gimmick - cos if the wind shifts 15degrees it stops, and throws error "wind shift". Rubbish.

to be honest, I think I'd want some sort of error to happen on a 15 degree shift, there has to be a limit to wanting to follow the wind direction.

15 degrees is enough to want to either tack, free off for the mark or put the kite up depending on circumstances, which the limited brain of the machine will not know about.

The trouble is that different people will want different things. I think you will find that Ms McArthur's autopilots are bloody complex and take a lot of programming. We are talkiing about more amateur kit, which has to have software in it to suit some sort of 'average' expectations. Also a more limited learning curve required to use it!- Although as others have posted, all this kit is much better when you invest the time to set it up properly, and work out how to get the best from it.

Somebody would soon moan if it took them on a 25degree lift into the shallows, without raisning a windshift error.

For a cruising boat you may regard it as a gimmick (I might tend to agree), but the short handed racing enthusiasts seem to be able to make it work for them.

 

[Oyvind]

I quite agree with the above poster, that the wind shift alarm is definitely not a 'gimmick', but a necessary and desireable safety feature when sailing on the wind angle. Also, the AP does not stop working when the alarm goes off, but continues on the set wind angle. It is up to you to do something about the wind shift, i.e. either tack to take advantage of a lift, switch to compass course and ease out the sheets if it is no longer desireable or necessary to stay hard on the wind, or simply cancel the alarm and continue as you were.

Regarding the possibility of the AP luffing up, this has not been my experience with the advanced installation, and the AP is able to, depending on the AP settings, maintain a quite narrow track when hard on the wind. However, keeping to a narrow track will necessarily require more frequent rudder inputs, which again translates to higher battery drain so this is perhaps a racing mode rather than a cruising mode. But these are settings that can be changed at any time, and are well explained in the Raymarine manuals, and there is also a simple shortcut - pressing the -1 and +1 key simultaneously IIRC, that makes the AP steer a more 'relaxed' course with less rudder input.

Regarding auto tack, this is a great feature but one that may not work in a hard blow, simply because the AP does not turn the rudder over fast enough to make it through the tack. However, in the race I mentioned earlier, we heard that our competitors, one in an Open 50 with a very advanced ocean-racing setup, had the same problems with the auto tack feature under those conditions.

Regarding calibrating the AP, what nimbusgb said. Don't trust your dealer to have gone through the necessary sea trials and calibration routines before handover. Get out on the water on a calm day and go through all the calibration steps, which should be described in the manual, yourself to make sure that the system is properly set up for your boat.

PS: Not much of the above applies to my own, entry-level ST1000+ tiller pilot, which is underpowered (it came with the boat) and challenged in anything from a force 4 and up.

 

[tcm]

to be honest, I think I'd want some sort of error to happen on a 15 degree shift, there has to be a limit to wanting to follow the wind direction.

15 degrees is enough to want to either tack, free off for the mark or put the kite up depending on circumstances, which the limited brain of the machine will not know about.

The trouble is that different people will want different things. I think you will find that Ms McArthur's autopilots are bloody complex and take a lot of programming. We are talkiing about more amateur kit, which has to have software in it to suit some sort of 'average' expectations. Also a more limited learning curve required to use it!- Although as others have posted, all this kit is much better when you invest the time to set it up properly, and work out how to get the best from it.

Somebody would soon moan if it took them on a 25degree lift into the shallows, without raisning a windshift error.

For a cruising boat you may regard it as a gimmick (I might tend to agree), but the short handed racing enthusiasts seem to be able to make it work for them.

um, is an AP legal for racing? Not all racing anyway.

OK, it would be bettr if the error limit was user definable. So you can have an error at whatever wind angle you like.

 

[lw395]

um, is an AP legal for racing? Not all racing anyway.

OK, it would be bettr if the error limit was user definable. So you can have an error at whatever wind angle you like.

The general thing with autopilots is that there are a lot of variables in the steering algorithm, some of which you can adjust, some you can't and some that are only accessible via a shortcut on p72 of the manual. Otherwise you'd have a thing like a seventies rock band's mixing desk!

The more user adjustments, the more the user can make things worse and then moan about the **** product. I'm not an avid Raymarine fan, but I don't think this is any worse than any comparable product I've seen. I suppose 15 degrees is a reasonable error level, if you had to pick a number for all seasons.

Does anybody have a wind direction sensor much lower than masthead, and does it work any better when the boat starts pitching?

 

[Oyvind]

um, is an AP legal for racing? Not all racing anyway.
...

Yes, it is legal for single- and doublehanded racing. Which means that you can also use the AP if you race your yacht in the doublehanded class in a regular Tuesday afternoon club race. Well, at least it is legal here in Norway.